The Solent (/ˈsoʊlənt/ SOH-lənt) is a strait between the Isle of Wight and mainland Great Britain; the major historic ports of Southampton and Portsmouth lie inland of its shores.

[7] A pre-Celtic and supposedly Semitic root meaning "free-standing rock" has also been suggested as a possible description of the cliffs marking western approach of the strait.

[10][11] Seismic sounding has shown that, when the sea level was lower, the River Solent incised its bed to a depth of at least 46 metres (151 ft) below current Ordnance Datum.

[12][13] The Purbeck Ball Clay contains kaolinite and mica, showing that in the Lutetian stage of the Eocene water from a granite area, probably Dartmoor, flowed into the River Solent.

During the Ice Age, meanders of the Solent's tributaries became incised: for example, an incised meander of the River Test is buried under reclaimed land under the Westquay shopping centre, near Southampton docks;[14][15] Since the retreat of the most recent glaciation, the South East of England, like the Netherlands, has been steadily slowly sinking through historic time due to forebulge sinking.

It has an unusual double tide[20] that is both favourable and hazardous to maritime activities with its strong tidal movements and quickly changing sea states.

Coupled with the above, the Solent is renowned for its large volume of vessel usage, thus resulting in one of the highest density of declared lifeboat stations in the world.

This includes six RNLI (e.g. Calshot and Cowes) and five independently run stations (e.g. Hamble Lifeboat and Gosport and Fareham Inshore Rescue Service).

In the early 16th century, Henry VIII of England built an extensive set of coastal defences at each end of the Solent, part of his Device Forts, effectively controlling access to east and west.

The battle was inconclusive with no significant losses other than Henry VIII's flagship, the Mary Rose, which foundered and sank while making a sharp turn.

Musician Henry Purcell wrote "They that go down to the sea in ships" to be sung by the extraordinary voice of John Gostling in commemoration of this event.

According to the BBC, the 1⁄2 mi (800 m) tide[clarify] at Ryde gives a major advantage to hovercraft which can travel right up a beach and the Solent is the only place in Western Europe where there is a regular passenger service.